Known face seal assemblies for use in constructions having relatively rotating components, such as track roller assemblies of tracked machines, final drives, etc., typically comprise a pair of confronting seal rings of metal or other durable, hard material. The seal rings rotate relative to one another in face-to-face contact to provide a positive face seal which retains lubricant and prevents foreign matter from reaching rotating bearing surfaces of the rotating assembly. One such known seal assembly, which is particularly suited for use in a track roller assembly, comprises a first dynamic, i.e. axially movable, seal ring associated with a rotating track roller and a second dynamic seal ring associated with a non-rotating end collar of the track roller assembly. Each of the seal rings is axially-movable relative to its associated track roller assembly component and is biased toward the other seal ring by a resilient load ring or toric compressed between an angled ramp on the seal ring and a confronting angled ramp on the associated track roller or end collar. The force applied to each seal ring by its respective toric maintains the faces of the seal rings in constant sealing engagement.
A key factor in achieving a fluid-tight face seal is the compression of the torics between their associated ramps. Appropriate toric compression is required to create the face loading needed to maintain a positive seal. It is known in the art to provide a seal ring ramp with an 8 degree angled profile in combination with a confronting ramp having a 10 degree angled profile, with the angles converging in a direction away from the seal face of the subject seal ring. This converging 8/10 degree configuration provides good external pressure resistance, which avoids the effects of mud packing, for example, and also provides relatively flat load vs. deflection characteristics, which reduces large shifts in face loading as a result of axial movement of the seal rings. However, it has been discovered that optimal toric compression for certain seal sizes may require ramps longer than previously used. Accordingly, optimal toric compression utilizing the abovedescribed 8/10 degree seal construction may require greater axial space for the seal components, which precludes optimal toric compression in existing seal applications constructed for use with current, shorter seal ring ramps unless substantial modifications are made to the surrounding structure.
This invention is directed to overcoming one or more of the problems set forth above.